Creates Various miracles

We provide high quality diamond powder with our wonderful proprietary technology that has been highly evaluated by our customers.

Our History

New approaches

We create business from scratch, such as ozone water generation using diamond electrodes.

Product Search

We provide the most suitable products from our extensive lineup of diamond powder and sintered materials.

Usage search

We provide the most suitable products for your various applications.

Our Approach

We manufacture products with a high level of process control and quality control using our unique technology.?
We utilize our strengths as a pioneer in the field of industrial diamonds to meet a variety of needs.

Solving problems

Tomei responds and proposes solutions to customers' problems in a precise manner.

Tomei has advanced technology

Since our founding, we have faced many difficult problems together with our customers as a pioneer and developed products.
We will continue to work together with our customers to solve problems by utilizing the know-how of "materials," "technology," and "quality" that we have cultivated through this experience.

Diamond electrodes

We are challenging new possibilities by doping boron into diamond, which is an insulator and does not conduct electricity, and using it as a diamond electrode.

Generates ozone water

Generates ozone water, which is safe and environmentally friendly Provides packages in the form of cells (modules) Supports from the material field Strengths of in-house development

Environmentally friendly

Ozone water can be generated by electrolysis of water using conductive diamond electrodes. Ozonated water is water that contains ozone and OH (hydroxyl radical) dissolved in it, and is highly effective in sterilizing, killing viruses, and decomposing persistent organic matter. When compared to air and water, ozone dissolved in water has more molecules and is more effective at the same concentration.
It is also safer than ozone gas, easier to handle because it is a liquid, and more effective on the target object.

Product Lineup

We provide the most suitable products for customers from a wide range of products.

Diamond Powder Diamond powder

Diamond Powder

DIAMOND POWDER for industrial uses that has been subjected to a high level of process and quality control. It is used as a material for precision processing tools in the fields of semiconductors, automobiles, machinery, and civil engineering and construction.

Other product list
cBN Powder cBN powder

cBN Powder

cBN powder is an abrasive grain with hardness second only to diamond. It is superior to diamond in thermal stability, and is used as a material for grinding tools for difficult-to-cut iron-based materials in the automotive field.

Other product list
Sintered diamond PCD

Diamond sintered compact

PCD is a tool and wear-resistant material made by sintering diamond powder and cemented carbide using a high-temperature, high-pressure method. It has higher toughness than single-crystal diamond, and is used as a material for cutting and grinding tools for non-ferrous metals in the automotive and mechanical fields.

Other product list
cBN sintered body PcBN

cBN sintered body

This is a tool material made by sintering cBN powder mixed with binder and cemented carbide using a high-temperature, high-pressure method. It is used as a material for cutting and grinding tools for ferrous metals in the automobile and machinery fields.

Other product list
Special Sintered Body Special sintered body

Special sintered body

This is a special sintered body product that utilizes our own high-temperature, high-pressure synthesis equipment. We also handle sintered bodies in large sizes. These are special diamond sintered bodies intended to replace cemented carbide tools in the automotive and mechanical fields.

Other product list

Diamond Plates

A 100% carbon diamond substrate synthesized by the CVD method without any binder. We offer a wide range of diamond plates for tools, heat dissipation materials, and research materials.

Other product list


Frequently asked questions are summarized below. If you do not find a question, please feel free to contact us.

What kind of abrasive grain evaluation do you perform?

In addition to general grain size control, we conduct quality control using our own know-how on coarse and fine grain control, as well as quality control using various inspection machines including shape and composition.

Is it possible to make custom orders for diamond/cBN powder?

We have been responding to custom orders from customers since our establishment, including specification of grain size and shape and additional processing of abrasive grains. We will make use of our strength as a manufacturer to offer various proposals.。

Is it possible to respond to custom orders for sintered diamond/cBN?

We are working on various custom orders as a manufacturer, such as changing the composition and shape of abrasive grains as well as the overall thickness and the thickness of diamond and cBN layers. Please contact us first.

Is it possible to provide samples?

Depending on the type, we can provide samples. Please feel free to contact us.

What is the minimum sales unit for diamond powder and cBN powder?

It may vary depending on the product, but generally, the smallest unit we handle is 100ct (20g). For more details, please contact us.

How long does it take for delivery?

If the item is in stock, it can be shipped in one to two days. If the product is not in stock, the delivery time varies greatly depending on the product, so please contact us first.

Is it possible to have technical cooperation?

We have a lot of experience in product development with many customers. Please contact us for more information.

Is it possible to do business directly with you? Do you deal through a distributor?

We do not have a specific distributor in Japan. We can deal with you directly or through a designated trading company. As for overseas, we have agents in each country, so please consult with us.

Do you sell tool products such as grinding wheels and cutting tools?

We are a materials manufacturer and provide materials for diamond tools and cBN tools, so we do not deal in tools. However, we can introduce you to manufacturers that we do business with.

Do you sell in natural diamond powder?

We only deal with synthetic diamond powder for industrial use.

I would like to have a meeting with a sales person.

Please fill out the necessary information and outline of your project on the Contact Us page. One of our sales representatives will contact you as soon as possible.

For more information, please contact us at Tomei.
Contact and Support

From inquiries about our products to consultations about their applications We provide products and services to meet the needs of companies that are considering developing products using industrial diamonds.